Make CereStation eligible for random map selection on 60+ players (#23206)

code/modules/mapping/base_map_datum.dm

@@ -16,3 +16,5 @@
 	var/webmap_url
 	/// Is this map voteable?
 	var/voteable = TRUE
+	/// Minimum amount of players required for this map to be eligible in random map picks.
+	var/min_players_random = 0

code/modules/mapping/cerestation.dm

@@ -3,3 +3,4 @@
 	technical_name = "CereStation"
 	map_path = "_maps/map_files/cerestation/cerestation.dmm"
 	webmap_url = "https://affectedarc07.github.io/SS13WebMap/Paradise/CereStation/"
+	min_players_random = 60